Is bed rest during pregnancy a crock?

The very idea of bed rest during pregnancy seems so retro, the sort of prescription more typical of days gone by. And yet, bed rest is still routinely prescribed for a smorgasbord of complications, from high blood pressure to risk of preterm labour. It can last from a few days to several months, and the range of restriction can also vary from modified (life in slow motion), to complete (bathroom privileges only), to — in extreme cases — hospitalization.

Is there medical proof that it works?

At face value, bed rest seems like a logical intervention. The conventional wisdom is that lying flat reduces stress on the uterus and cervix. While doctors in Canada and the United States continue to prescribe it, some experts say there’s little medical proof that it makes a blind bit of difference, and are trying to limit the frequency with which bed rest is prescribed.

“I think it was very common to say that bed rest would help prolong the pregnancy and cure many things that were going wrong,” says Howard Berger, head of maternal fetal medicine at St. Michael’s Hospital in Toronto. “But over time, we know that there is no evidence to support that.” Berger says only extreme scenarios warrant total bed rest, citing a triplet pregnancy with an open cervix and bulging amniotic membranes at 24 weeks, as one such case where he prescribed it. For routine complications, he never recommends it.

Why do doctors still prescribe bed rest?

But Haim Abenhaim, a maternal and fetal medicine specialist and director of perinatal research at Montreal’s Jewish General Hospital, begs to differ. “The reason we don’t have quality scientific evidence is because it is essentially impossible to carry out research on women who are considered candidates for bed rest,” he says. “No doctor would subject a patient to a trial when there is a rational argument for her not going about her regular activity.”

Scant evidence on the subject explains why there is so much variation in practice, he says. “If you ask 20 doctors for their views on bed rest, you will probably get 20 different responses.”

While Abenhaim agrees that total bed rest is not a solution to all pregnancy complications, he regularly prescribes it in his high-risk practice in cases of an incompetent cervix or where there is increased risk of preterm delivery.

“Just because we don’t have quality evidence doesn’t mean there’s no benefit to bed rest,” he says. “We base our logic on the pure mechanics. You limit the effect of gravity and increase blood flow to the uterus.”

Is there any harm in bed rest?

“Women don’t want to blame themselves and doctors don’t want to be blamed,” Berger says. “Even if it’s not proven — and there’s no way it can be proven scientifically — you still want to be perceived as doing everything you possibly can.”

And herein lies the crux of the issue: Doctors revert to bed rest when there is no “magic pill” to cure a condition. And no mother is willing to gamble with the life of her child. So, thousands of pregnant women find themselves in bed each year.

“Many physicians will say, ‘What harm can there be?’” Berger says. “‘Let’s take every precaution possible. So let’s take this woman off work, let’s tell her to lie in bed and that way I’m perceived to be doing everything possible, and then if something bad happens then at least I’ve done what I can.’”

The problem, however, is that this apparently benign treatment comes loaded with physical and psychological risks for the mother, such as blood clots in the legs, cardiac deconditioning, decreased muscle mass and depression.

“There is currently no evidence to support the prescription of bed rest for pregnancy complications, but there is extensive evidence of its adverse side effects,” says Judith Maloni, a professor of nursing at Case Western Reserve University, in Cleveland, Ohio, who has been researching pregnancy and bed rest since 1989. She cites muscle atrophy, bone loss, dizziness, dehydration and, well, misery among the risks.

Are doctors aware of the risks?

Maloni says many physicians aren’t aware of the research done on the dangerous side effects of bed rest and continue to prescribe it widely. “This is what they have always done, and they haven’t changed their practice to match current evidence,” she says.

“Things change very slowly in medicine, and in obstetrics specifically,” concedes Berger. “So I think that some of these notions are still practised for that reason.”

Does bed rest work?

“Can I say with certainty that bed rest is the reason my pregnancy was successful? No. But mentally, it made a huge difference,” says Uma Yates,* a mother who was prescribed bed rest due to premature rupture of the amniotic membranes early in her second trimester.

Yates was told that her condition was rare in early pregnancy, and that the outcome was usually not good. She was put on bed rest, the fluid leakage stopped, and after six fraught weeks, the doctors became confident that the membranes had resealed and she was free to return to work and her regular life. “It turns out we were one of the lucky few.”

“When you trust your doctor, and he tells you to go to bed, you go to bed,” says Megan Valm,* who spent eight weeks in her third trimester on bed rest because she was dilating and having early contractions.

Valm’s son was born at 36 weeks, just two days after she came off bed rest. “Who knows how early he might have come if I hadn’t gone on bed rest,” she says. “I just wasn’t prepared to take any risks.”

Why do women still go on bed rest during pregnancy?

“It’s so typical of women, and especially typical of mothers, to say: ‘Oh, I’ll give up everything for my baby,’ because that’s what mothers do across their lifetime. They feel guilty when they call attention to themselves,” says Maloni. “But I don’t think you have to make the either/or choice.”

She suggests women who are prescribed bed rest have a frank conversation with their health-care providers about the potential risks and how to avoid them, and to seek a second opinion from someone who specializes in high-risk pregnancies.

Are there alternatives?

“I think we [doctors] need to exercise judgment when prescribing bed rest,” says Abenhaim, adding that restricted activity, rather than complete bed rest, may be more reasonable in certain situations.

“Often, there are modifications that are needed to a woman’s lifestyle during pregnancy due to certain complications, and these need to be tailored to the specific condition,” echoes Berger, citing lifting, standing and the way we commute to work as activities that can be modified. “But a blanket statement of bed rest can be misinterpreted by the patient and can lead to complications.”

Berger says more medical residents are now being taught about the potential harm that can come to a mother on bed rest, and he’s hopeful that instances of its prescription are on the decline.

*Names have been changed.

A version of this article appeared in our November 2012 issue.

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